Double-gate Carbon Nanotube Field Research Articles

Impact of thermally -aware environmental conditions on double gate carbon nanotube FET

In this paper, a temperature dependent analytical model of double gate carbon nanotube field effect transistor (DG-CNTFET) has been developed to evaluate the performance of DG-CNTFET under variable thermal environmental conditions. Using the developed model, I–V characteristics of DG-CNTFET have been obtained by nano-TCAD ViDES (nano-Technology Computer Aided Design ViDES) simulator. Further, the effect of temperature on other performance parameters such as output characteristics, ON current, OFF current, subthreshold swing and drain conductance have also been obtained for a temperature ranging from 250 K to 350 K. It has been observed that with increase in temperature, drain current rises which further influence the I–V characteristics of DG-CNTFET. From results, it is revealed that the ON current and drain conductance of DG-CNTFET gets increased with variable temperature. Further, it is also presented in paper that subthreshold swing is also increased under variable thermal environment conditions.

One instruction set computer with optimised polarity‐tunable model of double gate CNTFETs

Emerging devices such as double gate carbon nanotube field effect transistors (DG CNTFETs) have opened up manifold possibilities for reconfigurable logic design. The thickness of gate oxide and the employment of inhomogeneous dielectrics over and under the carbon nanotubes (CNTs) impact the operation of DG CNTFETs. In this work, the dielectric constant and the thickness of the gate oxide are optimised to suppress the ambipolar conduction in CNTFETs. A multi-objective genetic algorithm-based approach is proposed to optimise these parameters. The contributions in this study are two-fold: firstly, a DG CNTFET is fabricated with the optimised parameters. By exploiting the ability to select the conduction behaviour using a second gate in the fabricated DG CNTFETs, the device is electrostatically programmed to behave as an n or p-type CNTFET. Secondly, a one instruction set computer is simulated with the optimised model of DG CNTFET. A universal static logic cell which implements 16 logic functions, a D-Latch and a D-FF were built with DG CNTFETs. The logic circuits with polarity-tunable DG CNTFETs outperform other logic structures. There is a 40% betterment in performance primarily due to the reduced number of logic levels and by 25% due to the reduced delay.

New Optimized Reconfigurable ALU Design Based on DG-CNTFET Nanotechnology

<p>The heart of the microprocessor and responsible for the execution of logical and arithmetic operations, the arithmetic and logical unit is constantly optimized. The performance is improved to allow the development of more powerful and smaller circuits. This paper describes simple ALU but contains the essentials functions. It is a reconfigurable ALU based on double-gate carbon nanotube field effect transistor (DG-CNTFETs). This transistor has an interesting property, it can switch from p- to n- type behavior and vice-versa dynamically. This opens the opportunity for building novel and complex functions in fine-grain reconfigurable logic inaccessible to MOSFETs and reaching a good performance levels. In literature there are several problems related to signal quality. In this paper, we will propose a new solution that allows us to improve the quality of the output signal without affecting the number of transistors used. This improves the overall performance of ALU. We will show the improvement in signal level and quality. First, an overview of carbon nanotube field-effect transistor (CNTFET) and state of the art Reconfigurable ALU based on DG-CNTFET is given. Then an explication of signal integrity issues of the actual Reconfigurable DG-CNTFET cell is done. After we will present and explain the proposed solution. The solution is first applied on the cnt_9T circuit then will show its effect on the ALU. Finally, a performance comparison is made.</p>

New Optimized Reconfigurable ALU Design Based on DG-CNTFET Nanotechnology

<p>The heart of the microprocessor and responsible for the execution of logical and arithmetic operations, the arithmetic and logical unit is constantly optimized. The performance is improved to allow the development of more powerful and smaller circuits. This paper describes simple ALU but contains the essentials functions. It is a reconfigurable ALU based on double-gate carbon nanotube field effect transistor (DG-CNTFETs). This transistor has an interesting property, it can switch from p- to n- type behavior and vice-versa dynamically. This opens the opportunity for building novel and complex functions in fine-grain reconfigurable logic inaccessible to MOSFETs and reaching a good performance levels. In literature there are several problems related to signal quality. In this paper, we will propose a new solution that allows us to improve the quality of the output signal without affecting the number of transistors used. This improves the overall performance of ALU. We will show the improvement in signal level and quality. First, an overview of carbon nanotube field-effect transistor (CNTFET) and state of the art Reconfigurable ALU based on DG-CNTFET is given. Then an explication of signal integrity issues of the actual Reconfigurable DG-CNTFET cell is done. After we will present and explain the proposed solution. The solution is first applied on the cnt_9T circuit then will show its effect on the ALU. Finally, a performance comparison is made.</p>

Performance Analysis Of Double-Gate Carbon-Nanotube FET And MOSFET For High Speed Integrated Circuits Design

This paper explains the detailed structure as well as performance of DG-CNTFET (Double Gate Carbon Nanotube Field Effect Transistor) and its performance is compared with the DG-MOSFET (Double Gate Metal Oxide Semiconductor Field Effect Transistor). Various parameters like I-V characteristics, ON current, OFF current and ON to OFF current ratio have been evaluated using nano-TCAD ViDES. Also, the transport description of DG-MOSFET and DG-CNTFET has been described in detail. It has been observed that DG-CNTFET has lower OFF current and higher ON current in comparison to the DG-MOSFET. The higher ON current of DG-CNTFET depicts that it requires less time to turn on the device in comparison with DG-MOSFET. Also, OFF current of the DG-CNTFET is lesser as compared to MOSFET. The DG-CNTFET’s higher ON to OFF current ratio outperforms the DG-MOSFET in term of switching speed of the device. It is proposed that CNTFET can be used as an alternative of MOSFETs for high speed Integrated Circuit (IC) design.

FPGA Design with Double-Gate Carbon Nanotube Transistors

Double-gate carbon nanotube field effect transistors (DG-CNTFETs) are novel devices showing an interesting property that consists of controlling the p- or n-type behavior during the device operation. This opens up the opportunity for novel design paradigms. Based on a compact physical model of these devices, we demonstrate the superiority of field-programmable gate arrays (FPGAs) designed with fine-grain DG-CNTFETs compared to FPGAs designed with traditional circuits and with coarse-grain DG-CNTFETs by 13% to 48% respectively in terms of delay.

Molecular electronics and reconfigurable logic

This paper describes a reprogrammable architecture based on regular matrices of fine-grain dynamically reconfigurable cells based on double-gate carbon nanotube field effect transistors (DG-CNTFET) exhibiting ambivalence (p-type or n-type behaviour depending on the back-gate voltage). Using available models, reconfigurable cells have been simulated and performance metrics quantified at 4 GHz operation. A function mapping method suitable for this matrix structure has been devised, and various interconnect topologies have been analysed, showing average mapping success rates to 4 × 4 cell matrices of above 80% for 8-node function graphs. This gives insight into the way data functionality could be coded into the architecture based on such reconfigurable cells for on-the-fly and partial reprogrammability.